%I #8 Jun 22 2020 07:03:33
%S 1,2,7,60,3444,11402948,129187106461769
%N Number of lattice congruences of the weak order on the Coxeter group S_n (the symmetric group).
%C To a very good approximation for n=4,5,6 we have a(n+1) ~ (a(n))^2.
%H Nathan Reading, <a href="http://arXiv.org/abs/math.CO/0401404">Lattice congruences of the weak order</a>, arXiv:math/0401404 [math.CO], 2004.
%Y Cf. A091688, A330039.
%K nonn,hard,more
%O 1,2
%A Nathan Reading (nreading(AT)umich.edu), Jan 28 2004
